Luke: How did my father die?
Obi-Wan: A young Jedi named Darth Vader, who was a pupil of mine until he turned to evil, helped the Empire hunt down and destroy the pizza delivery guys. He betrayed and robbed your father.

Darth Vader : You should not have come back!

-"The glass is neither half-full nor half-empty: it's twice as big as it needs to be."